As known, a woman's menstrual cycle lasts about four weeks and there are more than enough reasons to suppose that her human ovule can be fertilized at any time within 12 hours following its ovulation. In its ovulation, the ovule is ejected out of the ovary and begins to migrate inside the feminine genital organs. If, during the 12-hour time interval, the ovule has not been reached by a spermatozoon, it will be destroyed.
Despite the fact that the mechanism of menstruation is respetitive and commonly known as a period, it appears irregularly most times. A cycle lasts, in general, from 27 to 30 days, while menstruation lasts from 3 to 7 days in the cycle. At least the variation in the cycle duration may be due to climatological and psychic influences.
The point where the ovule and the spermatozoon generally meet is the lower third of the feminine genital duct. During ejaculation, the seminal fluid enters the back portion of the vagina and the spermatozoon in the seminal fluid then begin to migrate upwards along the mucous membrana coating the duct. During this migration of from 15 to 20 cm to the ovaries, most of the spermatozoon die. Those which are stronger may meet and fertilize a live ovule. The rest continue migrating until their complete exhaustion, being finally phagocyted by white cells. The spermatozoon maintain their fertilizing capability for about 30 hours, at most, even though they move inside a woman's womb for about 48 hours.
Because the spermatozoon and ovule have very short lives, 30 hours and 12 hours, respectively, after being ejaculated and ejected from the ovary, and the time of such ovary ejection is variable, the possibility of such fertilization within a menstrual cycle is limited. It only exists from just before (18 hours) to immediately after (12 hours) ovulation, which takes place approximately at the midpoint of the cycle, between 17 and 12 days before the next menstruation, thereby defining fertile and sterile periods in the menstrual cycle.
As long ago as 1976, well-reputed scientists from the Universities of Ontario, in Canada, Haifa, in Israel, and Auckland, in New Zealand, announced researches carried out on women's saliva during their menstrual cycles. They observed a clear difference in the cell pattern in saliva between fertile and sterile periods. Since then, a great number of scientists at other universities of the world joined in the aforementioned researches, also finding a clear difference in women's saliva between fertile and sterile periods, and possibly detecting diseases and irregularities in the gynaecological system as well. At least 153 scientists at 41 universities from 1976 to 1985 have verified this fertility indicating system. Their researches have, up to now, always been carried out in the laboratory, however.
This research shows that saliva crystallization appears when the blood folliculin level has reached a certain height that coincides with the third or fourth day before ovulation. The crystallization lasts until 3 or 4 days after ovulation, when the presence of lutein inhibits the crystallization. Due to this, the crystallization even indicates fertile period, since it takes place from 3 or 4 days before ovulation up to 3 or 4 days after it.
As a matter of information, a list of researches carried out in 1985 concerning this subject is detailed hereinafter:
Drs. Tho, S. P., Scholer, J., Phung, B. V., Harp, R. J., and McDnough, P. G., "Radioimmunoassay of progesterone in saliva: a simplified technique using 1251-radio-ligand." Dep. of Obstetrics and Gynaecology, Medical College of Georgia, Augusta, Ga., UNITED STATES.
Drs. Campbell, W. G., Priest, R. E., and Weathers D. R., "Characterization of two of crystalloids in pleomorphic adenomas of minor salivary glands. A light microscopic," Dept. of Pathology, Emory University School of Medicine, Atlanta, Ga., UNITED STATES.
Drs. Belkien, L. D., Bordt J., Moeller P., Hano R., and Nieschiag E., "Estradiol in saliva for monitoring follicular stimulation in an in vitro fertilization program," Max Planck Clinical Research Unit for Reproductive Medicine, Muenster, FEDERAL REPUBLIC OF GERMANY.
Drs. Walker, R. F., Wilson, D. W., Truran, P. L., Read, G. F., and Richards, C. "Characterization of profiles of salivary progesterone concentrations during the luteal phase of fertile and subfertile women," Tenovus Institute for Cancer Research, Welsh National School of Medicine, The Heath Cardiff, WALES.
Drs. Read, G. F., Bradely, J. A., Wilson, D. W., and Griffiths, K., "Evaluation of luteal-phase salivary progesterone levels in women with benign breast disease or primary breast cancer," Tenevous Institute for Cancer Research, Welsh National School of Medicine, Heath Park, Cardiff, WALES.
Drs. Sulfi, S. B., Donaldson, A., Gandy, S. C., Jeffcoste, S. L., and Chearskul, S., "Multicenter evaluation of assays for estradiol and progesterone in saliva," WHO Collaborating Centre, Chelsea Hospital for Women, London, ENGLAND.
Drs. Cedar, L., Nathan, C. Janssens, Y., Savale, M., and Guichard, A., "Salivary progesterone profile after in-vitro," ENGLAND.
As indicated above, the detection of a woman's fertile period during her menstrual cycle on the basis of the change in the structure of her saliva has only been carried out in the laboratory, which leads to a great difficulty in the determination of the salivary activity at an adequate moment and place in each cycle. The woman cannot make an auto-analysis and, thus, know her fertility period at any given moment.